We are working on an Arduino Board designed specifically for the electric car conversion crowd. I posted a summary of the project a while back over at Adafruit

As we work on the schematic, we noticed a few things things that might make our board (based on the new Mega 2560) more compatible with existing shields. Namely: the moved SPI pins.

I thought we would run this past the community to ensure we are not missing something. Again, from Adafruit forum:

"We were initially planning on sticking pretty close to the original header pinout. The Mega pinout, however, shows the SPI signals on header pins # 51, 52, 53 while the corresponding UNO SPI pins are on 12, 11, 13.

Unless there is a good reason that the Mega SPI pins are moved, I think we will put them in the same place as the UNO. Doing so will hopefully allow for more shield compatibility with our board."

SPI: 50 (MISO), 51 (MOSI), 52 (SCK), 53 (SS). These pins support SPI communication using the SPI library. The SPI pins are also broken out on the ICSP header, which is physically compatible with the Uno, Duemilanove and Diecimila.

Note: I just noticed that I wrote the wrong pin assignments above: 50, 51, 52, 53 on Mega corresponds to 12, 11, 13, 10 on UNO.

This would ensure that Duemilanove and UNO shields would be pin-compatible. There just seems to be a lot of shields out there that expect SPI on pins D11-13 still. Of course we will still have SPI on the ICSP header.

We were hoping you Arduino guys would get a kick out of the name we chose to call our board: "Macchina". Italians use it as a slang word for "car" (hopefully).

- Based on Arduino Mega- closer to Automotive specs, 4 layers, EMI protection, more fuses- on-board OBD2 interface with many protocols supported - including CANbus- can be hooked right up to car battery.